Template-free synthesis of metallic WS2 hollow microspheres as an anode for the sodium-ion battery

Abstract

In this work, an electrode has been proposed and designed on its interior structure and controlled morphology, Specifically, metallic WS2 hollow microspheres have been synthesized via a one-step solvothermal process, in the absence of additives, consisting of porous nanosheets with a large surface area. The individual nanosheet features an expanded interlayer distance of 1.02 nm and metallic characteristics, which can provide faster transport of electrons and reduce the diffusion pathway for sodium ions. Furthermore, the effects of anions in the ether-based electrolyte on the cycling performance were also investigated and optimized. As a result, such an anode can demonstrate superior capacitive behavior with excellent rate performance (388.2 mA h g−1 at 0.1 A g−1, 307.7 mA h g−1 at 1 A g−1) and long-term cycling stability (285 mA h g−1 at 2 A g−1 after 2000 cycles).